Inbred maize line NP2208

ABSTRACT

An inbred maize line, designated NP2208, the plants and seeds of inbred maize line NP2208, methods for producing a maize plant produced by crossing the inbred line NP2208 with itself or with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line NP2208 with another maize line or plant.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relatingto an inbred maize line designated NP2208.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine in a single variety or hybridvarious desirable traits. For field crops, these traits may includeresistance to diseases and insects, tolerance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination and stand establishment, growthrate, maturity, and plant and ear height, is important.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is cross-pollinated if the pollen comes from a flower ona different plant. Plants that have been self-pollinated and selectedfor type for many generations become homozygous at almost all gene lociand produce a uniform population of true breeding progeny. A crossbetween two different homozygous lines produces a uniform population ofhybrid plants that may be heterozygous for many gene loci. A cross oftwo plants each heterozygous at a number of gene loci will produce apopulation of hybrid plants that differ genetically and will not beuniform.

Maize (Zea mays L.), often referred to as corn in the United States, canbe bred by both self-pollination and cross-pollination techniques. Maizehas separate male and female flowers on the same plant, located on thetassel and the ear, respectively. Natural pollination occurs in maizewhen wind blows pollen from the tassels to the silks that protrude fromthe tops of the ears.

A reliable method of controlling male fertility in plants offers theopportunity for improved plant breeding. This is especially true fordevelopment of maize hybrids, which relies upon some sort of malesterility system. There are several options for controlling malefertility available to breeders, such as: manual or mechanicalemasculation (or detasseling), cytoplasmic male sterility, genetic malesterility, gametocides and the like. Hybrid maize seed is typicallyproduced by a male sterility system incorporating manual or mechanicaldetasseling. Alternate strips of two maize inbreds are planted in afield, and the pollen-bearing tassels are removed from one of theinbreds (female). Providing that there is sufficient isolation fromsources of foreign maize pollen, the ears of the detasseled inbred willbe fertilized only from the other inbred (male), and the resulting seedis therefore hybrid and will form hybrid plants.

The laborious, and occasionally unreliable, detasseling process can beavoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMSinbred are male sterile as a result of factors resulting from thecytoplasmic, as opposed to the nuclear, genome. Thus, thischaracteristic is inherited exclusively through the female parent inmaize plants, since only the female provides cytoplasm to the fertilizedseed. CMS plants are fertilized with pollen from another inbred that isnot male-sterile. Pollen from the second inbred may or may notcontribute genes that make the hybrid plants male-fertile. Seed fromdetasseled fertile maize and CMS produced seed of the same hybrid can beblended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown. There are severalmethods of conferring genetic male sterility available, such as multiplemutant genes at separate locations within the genome that confer malesterility, as disclosed in U.S. Pat. Nos. 4,654,465 and 4,727,219 toBrar et al. and chromosomal translocations as described by Patterson inU.S. Pat. Nos. 3,861,709 and 3,710,511. These and all patents referredto are incorporated by reference.

There are many other methods of conferring genetic male sterility in theart, each with its own benefits and drawbacks. These methods use avariety of approaches such as delivering into the plant a gene encodinga cytotoxic substance associated with a male tissue specific promoter oran antisense system in which a gene critical to fertility is identifiedand an antisense to that gene is inserted in the plant (see:Fabinjanski, et al. EPO 89/3010153.8 publication no. 329,308 and PCTapplication PCT/CA90/00037 published as WO 90/08828).

Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals affect cells that are criticalto male fertility. The application of these chemicals affects fertilityin the plants only for the growing season in which the gametocide isapplied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application ofthe gametocide, timing of the application and genotype specificity oftenlimit the usefulness of the approach.

The use of male sterile inbreds is but one factor in the production ofmaize hybrids. The development of maize hybrids requires, in general,the development of homozygous inbred lines, the crossing of these lines,and the evaluation of the crosses. Pedigree breeding and recurrentselection breeding methods are used to develop inbred lines frombreeding populations. Breeding programs combine the genetic backgroundsfrom two or more inbred lines or various other germplasm sources intobreeding pools from which new inbred lines are developed by selfing andselection of desired phenotypes. The new inbreds are crossed with otherinbred lines and the hybrids from these crosses are evaluated todetermine which of those have commercial potential. Plant breeding andhybrid development are expensive and time consuming processes.

Pedigree breeding starts with the crossing of two genotypes, each ofwhich may have one or more desirable characteristics that is lacking inthe other or which complements the other. If the two original parents donot provide all the desired characteristics, other sources can beincluded in the breeding population. In the pedigree method, superiorplants are selfed and selected in successive generations. In thesucceeding generations the heterozygous condition gives way tohomogeneous lines as a result of self-pollination and selection.Typically in the pedigree method of breeding five or more generations ofselfing and selection is practiced: F1 to F2 ; F3 to F4; F4 to F5, etc.

A single cross maize hybrid results from the cross of two inbred lines,each of which has a genotype that complements the genotype of the other.The hybrid progeny of the first generation is designated F1. In thedevelopment of commercial hybrids only the F1 hybrid plants are sought.Preferred F1 hybrids are more vigorous than their inbred parents. Thishybrid vigor, or heterosis, can be manifested in many polygenic traits,including increased vegetative growth and increased yield.

The development of a maize hybrid involves three steps: (1) theselection of plants from various germplasm pools for initial breedingcrosses; (2) the selfing of the selected plants from the breedingcrosses for several generations to produce a series of inbred lines,which, although different from each other, breed true and are highlyuniform; and (3) crossing the selected inbred lines with differentinbred lines to produce the hybrid progeny (F1). During the inbreedingprocess in maize, the vigor of the lines decreases. Vigor is restoredwhen two different inbred lines are crossed to produce the hybridprogeny (F1). An important consequence of the homozygosity andhomogeneity of the inbred lines is that the hybrid between a definedpair of inbreds will always be the same. Once the inbreds that give asuperior hybrid have been identified, the hybrid seed can be reproducedindefinitely as long as the homogeneity of the inbred parents ismaintained.

A single cross hybrid is produced when two inbred lines are crossed toproduce the F1 progeny. A double cross hybrid is produced from fourinbred lines crossed in pairs (A×B and C×D) and then the two F1 hybridsare crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F1hybrids is lost in the next generation (F2). Consequently, seed fromhybrids is not used for planting stock.

Hybrid seed production requires elimination or inactivation of pollenproduced by the female parent. Incomplete removal or inactivation of thepollen provides the potential for self pollination. This inadvertentlyself pollinated seed may be unintentionally harvested and packaged withhybrid seed. Once the seed is planted, it is possible to identify andselect these self pollinated plants. These self pollinated plants willbe genetically equivalent to the female inbred line used to produce thehybrid. Typically these self pollinated plants can be identified andselected due to their decreased vigor. Female selfs are identified bytheir less vigorous appearance for vegetative and/or reproductivecharacteristics, including shorter plant height, small ear size, ear andkernel shape, cob color, or other characteristics.

Identification of these self pollinated lines can also be accomplishedthrough molecular marker analyses. See, "The Identification of FemaleSelfs in Hybrid Maize: A Comparison Using Electrophoresis andMorphology", Smith, J. S. C. and Wych, R. D., Seed Science andTechnology 14, pp. 1-8 (1995), the disclosure of which is expresslyincorporated herein by reference. Through these technologies, thehomozygosity of the self pollinated line can be verified by analyzingallelic composition at various loci along the genome. Those methodsallow for rapid identification of the invention disclosed herein. Seealso, "Identification of Atypical Plants in Hybrid Maize Seed byPostcontrol and Electrophoresis" Sarca, V. et al., Probleme de GeneticaTeoritca si Aplicata Vol. 20 (1) p. 29-42.

As is readily apparent to one skilled in the art, the foregoing are onlytwo of the various ways by which the inbred can be obtained by thoselooking to use the germplasm. Other means are available, and the aboveexamples are illustrative only.

Maize is an important and valuable field crop. Thus, a continuing goalof plant breeders is to develop high-yielding maize hybrids that areagronomically sound based on stable inbred lines. The reasons for thisgoal are obvious: to maximize the amount of grain produced with theinputs used and minimize susceptibility of the crop to pests andenvironmental stresses. To accomplish this goal, the maize breeder mustselect and develop superior inbred parental lines for producing hybrids.This requires identification and selection of genetically uniqueindividuals that occur in a segregating population. The segregatingpopulation is the result of a combination of crossover events plus theindependent assortment of specific combinations of alleles at many geneloci that results in specific genotypes. The probability of selectingany one individual with a specific genotype from a breeding cross isinfinitesimal due to the large number of segregating genes and theunlimited recombinations of these genes, some of which may be closelylinked. However, the genetic variation among individual progeny of abreeding cross allows for the identification of rare and valuable newgenotypes. These new genotypes are neither predictable nor incrementalin value, but rather the result of manifested genetic variation combinedwith selection methods, environments and the actions of the breeder.

Thus, even if the entire genotypes of the parents of the breeding crosswere characterized and a desired genotype known, only a few, if any,individuals having the desired genotype may be found in a largesegregating F2 population. Typically, however, neither the genotypes ofthe breeding cross parents nor the desired genotype to be selected isknown in any detail. In addition, it is not known how the desiredgenotype would react with the environment. This genotype by environmentinteraction is an important, yet unpredictable, factor in plantbreeding. A breeder of ordinary skill in the art cannot predict thegenotype, how that genotype will interact with various climaticconditions or the resulting phenotypes of the developing lines, exceptperhaps in a very broad and general fashion. A breeder of ordinary skillin the art would also be unable to recreate the same line twice from thevery same original parents as the breeder is unable to direct how thegenomes combine or how they will interact with the environmentalconditions. This unpredictability results in the expenditure of largeamounts of research resources in the development of a superior new maizeinbred line.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred maize line,designated NP2208. This invention thus relates to the seeds of inbredmaize line NP2208, to the plants of inbred maize line NP2208, and tomethods for producing a maize plant by crossing the inbred line NP2208with itself or another maize line. This invention further relates tohybrid maize seeds and plants produced by crossing the inbred lineNP2208 with another maize line.

The invention is also directed to inbred maize line NP2208 into whichone or more specific, single gene traits, for example transgenes, havebeen introgressed from another maize line. Preferably, the resultingline has essentially all of the morphological and physiologicalcharacteristics of inbred maize line of NP2208, in addition to the oneor more specific, single gene traits introgressed into the inbred,preferably the resulting line has all of the morphological andphysiological characteristics of inbred maize line of NP2208, inaddition to the one or more specific, single gene traits introgressedinto the inbred. The invention also relates to seeds of an inbred maizeline NP2208 into which one or more specific, single gene traits havebeen introgressed and to plants of an inbred maize line NP2208 intowhich one or more specific, single gene traits have been introgressed.The invention further relates to methods for producing a maize plant bycrossing plants of an inbred maize line NP2208 into which one or morespecific, single gene traits have been introgressed with themselves orwith another maize line. The invention also further relates to hybridmaize seeds and plants produced by crossing plants of an inbred maizeline NP2208 into which one or more specific, single gene traits havebeen introgressed with another maize line.

DEFINITIONS

In the description and examples that follow, a number of terms are usedherein. In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided. Below are the descriptors usedin the data tables included herein. All linear measurements are incentimeters unless otherwise noted.

    ______________________________________                                        Heat units                                                                           (Max Temp(≦86 deg. F.) + Min Temp(≧50 deg. F.))/2 -             50                                                                       EMRGN Final number of plants per plot                                         KRTP Kernel type: 1. sweet 2. dent 3. flint 4. flour 5. pop                    6. ornamental 7. pipecorn 8. other                                           ERTLP % Root lodging (before anthesis)                                        GRNSP % Brittle snapping (before anthesis)                                    TBANN Tassel branch angle of 2nd primary lateral branch (at anthesis)               LSPUR Leaf sheath pubescence of second leaf above the ear (at                  anthesis) 1-9 (1 = none)                                               ANGBN Angle between stalk and 2nd leaf above the ear (at anthesis)                  CR2L Color of 2nd leaf above the ear (at anthesis)                      GLCR Glume Color                                                              GLCB Glume color bars perpendicular to their veins (glume bands):                    1. absent 2. present                                                   ANTC Anther color                                                             PLQUR Pollen Shed: 0-9 (0 = male sterile)                                     HU1PN Heat units to 10% pollen shed                                           HUPSN Heat units to 50% pollen shed                                           SLKC Silk color                                                               HU5SN Heat units to 50% silk                                                  SLK5N Days to 50% silk in adapted zone                                        HU9PN Heat units to 90% pollen shed                                           HUPLN Heat units from 10% to 90% pollen shed                                  DA19 Days from 10% to 90% pollen shed                                         LAERN Number of leaves above the top ear node                                 MLWVR Leaf marginal waves: 1-9 (1 = none)                                     LFLCR Leaf longitudinal creases: 1-9 (1 = none)                               ERLLN Length of ear leaf at the top ear node                                  ERLWN Width of ear leaf at the top ear node at the widest point                     PLHCN Plant height to tassel tip                                        ERHCN Plant height to the top ear node                                        LTEIN Length of the internode between the ear node and the                     node above                                                                   LTASN Length of the tassel from top leaf collar to tassel tip                 LTBRN Number of lateral tassel branches that originate from the                      central spike                                                          EARPN Number of ears per stalk                                                APBRR Anthocyanin pigment of brace roots: 1. absent 2. faint                   3. moderate 4. dark                                                          TILLN Number of tillers per plant                                             HSKC Husk color 25 days after 50% silk (fresh)                                HSKD Husk color 65 days after 50% silk (dry)                                  HSKTR Husk tightness 65 days after 50% silk: 1-9 (1 = loose)                  HSKCR Husk extension: 1. short (ear exposed) 2. medium (8 cm)                  3. long (8-10 cm) 4. very long (>10 cm)                                      HEPSR Position of ear 65 days after 50% silk: 1. upright 2. horizontal               3. pendent                                                             STGRP % Staygreen at maturity                                                 DPOPN % dropped ears 65 days after anthesis                                   LRTRN % root lodging 65 days after anthesis                                   HU25 Heat units to 25% grain moisture                                         HUSG Heat units from 50% silk to 25% grain moisture in adapted                 zone                                                                         DSGM Days from 50% silk to 25% grain moisture in adapted zone                 SHLNN Shank length                                                            ERLNN Ear length                                                              ERDIN Diameter of the ear at the midpoint                                     EWGTN Weight of a husked ear (grams)                                          KRRWR Kernel rows: 1. indistinct 2. distinct                                  KRNAR Kernel row alignment: 1. straight 2. slightly curved 3. curved                ETAPR Ear taper: 1. slight 2. average 3. extreme                        KRRWN Number of kernel rows                                                   COBC Cob color                                                                COBDN Diameter of the cob at the midpoint                                     KRTP Endosperm type: 1. sweet 2. extra sweet 3. normal 4. high                 amylose 5. waxy 6. high protein 7. high lysine 8. super sweet                 9. high oil 10. other                                                        KRCL Hard endosperm color                                                     ALEC Aleurone color                                                           ALCP Aleurone color pattern: 1. homozygous 2. segregating                     KRLNN Kernel length (mm)                                                      KRWDN Kernel width (mm)                                                       KRDPN Kernel thickness (mm)                                                   K100N 100 kernel weight (grams)                                               KRPRN % round kernels on 13/64 slotted screen                                 GRLSR Grey leaf spot severity rating; 1 = resistent, 9 = susceptible.               INTLR Intactness rating of plants at time of harvest; 1 = all                foliage                                                                   intact, 9 = all plants broken below the ear.                                 LRTLP Percentage of plants lodged, leaning >30 degrees from                    vertical, but unbroken at harvest.                                           MST.sub.-- P Percent grain moisture at harvest.                               SCLBR Southern corn leaf blight severity rating; 1 = resistent,                      9 = susceptible.                                                       STKLP Percentage of plants with stalks broken below the ear at time                  of harvest.                                                            YBUAN Grain yield expressed as bushels per acre adjusted to 15.5%                    grain moisture.                                                        STBWR Stewart Bacterial Wilt                                                  ERLNN Ear Length                                                              CRSTR Common Rust Rating                                                    ______________________________________                                    

DETAILED DESCRIPTION OF THE INVENTION

Inbred maize lines are typically developed for use in the production ofhybrid maize lines. Inbred maize lines need to be highly homogeneous,homozygous and reproducible to be useful as parents of commercialhybrids. There are many analytical methods available to determine thehomozygotic and phenotypic stability of these inbred lines. The oldestand most traditional method of analysis is the observation of phenotypictraits. The data is usually collected in field experiments over the lifeof the maize plants to be examined. Phenotypic characteristics mostoften observed are for traits associated with plant morphology, ear andkernel morphology, insect and disease resistance, maturity, and yield.

In addition to phenotypic observations, the genotype of a plant can alsobe examined. There are many laboratory-based techniques available forthe analysis, comparison and characterization of plant genotype; amongthese are Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), and Simple SequenceRepeats (SSRs) which are also referred to as Microsatellites.

Some of the most widely used of these laboratory techniques are IsozymeElectrophoresis and RFLPs as discussed in Lee, M., "Inbred Lines ofMaize and Their Molecular Markers," The Maize Handbook,(Springer-Verlag, New York, Inc. 1994, at 423-432) incorporated hereinby reference. Isozyme Electrophoresis is a useful tool in determininggenetic composition, although it has relatively low number of availablemarkers and the low number of allelic variants among maize inbreds.RFLPs have the advantage of revealing an exceptionally high degree ofallelic variation in maize and the number of available markers is almostlimitless. Maize RFLP linkage maps have been rapidly constructed andwidely implemented in genetic studies. One such study is described inBoppenmaier, et al., "Comparisons among strains of inbreds for RFLPs",Maize Genetics Cooperative Newsletter, 65:1991, pg. 90, is incorporatedherein by reference. This study used 101 RFLP markers to analyze thepatterns of 2 to 3 different deposits each of five different inbredlines. The inbred lines had been selfed from 9 to 12 times before beingadopted into 2 to 3 different breeding programs. It was results fromthese 2 to 3 different breeding programs that supplied the differentdeposits for analysis. These five lines were maintained in the separatebreeding programs by selfing or sibbing and rogueing off-type plants foran additional one to eight generations. After the RFLP analysis wascompleted, it was determined the five lines showed 0-2% residualheterozygosity. Although this was a relatively small study, it can beseen using RFLPs that the lines had been highly homozygous prior to theseparate strain maintenance.

Inbred maize line NP2208 is a yellow dent maize inbred that is bestsuited as a male in crosses for producing first generation F1 maizehybrids. Inbred maize line NP2208 is best adapted to the Eastern Combeltand Mid-south regions of the United States. Hybrids made with NP2208experienced greensnap problems in the Western Cornbelt in 1998. Theinbred can be used to produce hybrids from approximately 104-112relative maturity based on the Comparative Relative Maturity RatingSystem for harvest moisture of grain. Inbred maize line NP2208demonstrates reliable late season plant health and average pollen shed,with only a few lateral branches. In hybrid combinations, NP2208demonstrates high yield for its maturity, sound seedling vigor, averageplant stature, improved stalk strength, average drydown, and has anattractive plant appearance. In hybrid combination, NP2208 alsodemonstrates acceptable resistance to Gray Leaf Spot, good resistance toNorthern Leaf Blight, good resistance to Stewart's Bacterial Wilt andLeaf Blight. For its area of adaptation, NP2208 demonstrates highyields, resistance to leaf diseases, consistent late season stalkstrength, and reliable seedling vigor.

The corn (Zea mays L.) Inbred NP2208 was derived from the three-waycross of BJJC417//4NA15/LH82. Parent BJJC417 is a proprietary NOVARTISSEEDS inbred derived from selfing within the F₂ of BJCD217/LH123. Parent4NA15 is a proprietary NOVARTIS SEEDS inbred derived fromself-pollinating within the three-way cross of BJCD217//0214/6N615.Parent LH82 is a Holden's Foundation Seeds, Inc. inbred derived from610/LH7. The inbred has been self-pollinated and ear-rowed a sufficientnumber of generations with careful attention paid to uniformity of planttype to ensure the homozygosity and phenotypic stability necessary touse in commercial production. The line has been increased both by handand in isolated fields with continued observation for uniformity. Novariant traits have been observed or are expected in NP2208. Inbredmaize line NP2208, being substantially homozygous, can be reproduced byplanting seeds of the line, growing the resulting maize plants underself-pollinating or sib-pollinating conditions with adequate isolation,and harvesting the resulting seed, using techniques familiar to theagricultural arts.

The production of hybrid maize lines typically comprises planting inpollinating proximity seeds of, for example, inbred maize line NP2208and of a different inbred parent maize plant, cultivating the seeds ofinbred maize line NP2208 and of said different inbred parent maize plantinto plants that bear flowers, emasculating the male flowers of inbredmaize line NP2208 or the male flowers of said different inbred parentmaize plant to produce an emasculated maize plant, allowingcross-pollination to occur between inbred maize line NP2208 and saiddifferent inbred parent maize plant and harvesting seeds produced onsaid emasculated maize plant. The harvested seed are grown to producehybrid maize plants.

Inbred maize line NP2208 can be crossed to inbred maize lines of variousheterotic group (see e.g. Hallauer et al. (1988) in Corn and CornImprovement, Sprague et al, eds, chapter 8, pages 463-564, incorporatedherein by reference) for the production of hybrid maize lines.

                                      TABLE 1                                     __________________________________________________________________________    VARIETY DESCRIPTION INFORMATION                                                 Inbred maize line NP2208 is compared inbred MO17                                                    INBRED NP2208   INBRED MO17                           __________________________________________________________________________    MATURITY                Days                                                                              Heat Units  Days                                                                              Heat Units                        __________________________________________________________________________      From emergence to 50% of plants in silk 59 1249.8  68 1470.1                  From emergence to 50% of plants in pollen 59 1251.2  64 1375.0                From 10% to 90% pollen shed 3 79.0  3 101.4                                 __________________________________________________________________________        Std Dev Sample Size  Std Dev Sample Size                                  __________________________________________________________________________      PLANT                                                                         cm Plant Height (to tassel tip) 218.0 53.90 65 210.6 49.60 65                 cm Ear Height (to base of top ear node) 75.2 22.80 65 83.6 21.8 65                                                             cm Length of Top Ear                                                         Internodenode 17.5 2.90                                                       11 015.1 1.91 11                                                               Average Number of                                                            Tillers 0.1 .30 11 0.1                                                        .30 11                        Average Number of Ears per Stalk 1.4 .50 50 1.3 45 50                         Anthocyanin of Brace Roots: 3   2                                             1 = Absent 2 = Faint 3 = Moderate 4 = Dark                                    LEAF                                                                          cm Width of Ear Node Leaf 9.5 .94 65 9.9 .55 65                               cm Length of Ear Node Leaf 76.7 4.48 65 70.9 5.85 65                          Number of leaves above top ear 6 .55 65 05 .38 65                             degrees Leaf Angle 38 11.48 11 43 18.47 11                                    (measure from 2nd leaf above ear at anthesis                                  to stalk above leaf)                                                        Leaf Color              2   (Munsell code 5GY 4/6)                                                                    2   (Munsell code 5GY 4/4)            Leaf Sheath Pubescence  4               4                                       (Rate on scale from 1 = none to 9 = like peach fuzz)                          Marginal Waves 3   5                                                          (Rate on scale from 1 = none to 9 = many)                                     Longitudinal Creases 4   3                                                    (Rate on scale from 1 = none to 9 = many)                                     TASSEL                                                                        Number of Primary Lateral Branches 2 1.17 65 6 1.15 65                        Branch Angle from Central Spike 15 11.18 11 46 10.02 11                       Cm Tassel Length 45.3 4.54 65 53.1 5.53 65                                    (from top leaf collar to tassel tip)                                          Pollen Shed 6   7                                                             (Rate on scale from 0 = male sterile to 9 = heavy shed)                     Anther Color            7   (Munsell code 5Y 8/8)                                                                     5   (Munsell code 2.5GY 8/6)                                                       Glume Color 5 (Munsell code                                                  2.5GY 8/8) 3 (Munsell code                                                    5GY 6/6)                          Bar Glumes (Glume Bands): 1 = Absent 2 = Present                                                      1               1                                       EAR (Unhusked Data)                                                         Silk Color (3 days after emergence)                                                                   11  (Munsell code 5R 5/8)                                                                     5   (Munsell code 2.5GY 8/6)                                                       Fresh Husk Color (25 days                                                    after 50% silking) 3 (Munsell                                                 code 5GY 6/6) 1 (Munsell code                                                 5GY 7/8)                            Dry Husk Color (65 days after 50% silking) 21 (Munsell code 2.5Y 8/4)                                                   21 (Munsell code 2.5Y 8/4)        Position of Ear at Dry Husk Stage:                                                                    2               2                                       1 = Upright 2 = Horizontal 3 = Pendent                                        Husk Tightness 4   6                                                          (Rate on scale from 1 = very loose to 9 = very tight)                         Husk Extension (at harvest): 2   2                                            1 = Short (ears exposed) 2 = Medium (<8 cm) 3 = Long                          (8-10 cm beyond ear tip) 4 = Very long (>10 cm)                               EAR (Husked Ear Data)                                                         cm Ear Length 13.4 1.16 64 18.4 1.77 65                                       mm Ear Diameter at mid-point 39.7 3.33 64 36.7 2.03 65                        gm Ear Weight 100.7 20.91 64 116.4 25.18 65                                   Number of Kernel Rows 14 1.55 64 11 1.05 65                                   Kernel Rows: 1 = Indistinct 2 = Distinct 2   2                                Row Alignment: 2   1                                                          1 = Straight 2 = Slightly Curved 3 = Spiral                                   cm Shank Length 10.9 2.06 13 13.1 2.07 13                                     Ear Taper: 1 = Slight 2 = Average 3 = Extreme 2   2                           KERNEL (Dried)                                                                mm Kernel Length 10.2 .74 13 10.3 1.18 13                                     mm Kernel Width 7.3 .73 13 8.9 .79 13                                         mm Kernel Thickness 4.2 .69 13 4.7 .62 13                                     % Round Kernels (Shape Grade) 34.7 20.07 13 57.2 18.29 13                     Aleurone Color Pattern: 1   1                                                 1 = Homozygous 2 = Segregating                                              Aleurone Color          18  (Munsell code)                                                                            18  (Munsell code)                      Hard Endosperm Color 8 (Munsell code 7.5YR 7/10) 7 (Munsell code 2.5YR                                                  8/10)                             Endosperm Type:         3               3                                       1 = Sweet (sul) 2 = Extra Sweet (sh2) 3 = Normal Starch                       gm Weight per 100 Kernels (unsized sample) 24.1 1.74 13 31.3 5.19 13                                                           COB                          mm Cob Diameter at mid-point 22.2 2.47 64 19.4 1.11 65                      Cob Color               23  (Munsell code 10R 5/8)                                                                    23  (Munsell code 10R 5/6)                                                         DISEASE RESISTANCE               (1 = most susceptible to 9 = most resistant)                                                          8               8                                       Common Rust (Puccinia sorghi)                                                 Stewart's Wilt (Erwinia stewartii) 6   8                                      AGRONOMIC TRAITS                                                              Stay Green (at 65 days after anthesis) 3   7                                  (rate on scale from 1 = worst to 9 = excellent)                               % Dropped Ears (at 65 days after anthesis) 0.0   0.7                          % Pre-anthesis Brittle snapping 3   0                                         % Pre-anthesis Root Lodging 1.2   2.0                                         % Post-anthesis Root Lodging 2.5   1.6                                        (at 65 days after anthesis)                                                   Kg/ha Yield of Inbred Per Se 3771.0   3926.5                                  (at 12-13% grain moisture)                                                  __________________________________________________________________________     In interpreting the foregoing color designations, reference may be had to     be made to the Munsell Glossy Book of Color, a standard color reference.      Color codes: 1.light green, 2.medium green, 3.dark green, 4.very dark         green, 5.green yellow, 6.pale yellow, 7.yellow, 8.yelow orange, 9.salmon,     10.pink orange, 11.pink, 12.light red, 13.cherry red, 14.red, 15.red and      white, 16.pale purple, 17.purple, 18.colorless, 19.white,  # 20.white         capped, 21.buff, 22.tan, 23.brown, 24.bronze, 25.variegated, 26.other.        Std Dev = Standard Deviation                                             

The invention also encompasses plants of inbred maize line NP2208 andparts thereof further comprising one or more specific, single genetraits which have been introgressed into inbred maize line NP2208 fromanother maize line. Preferably, one or more new traits are transferredto inbred maize line NP2208, or, alternatively, one or more traits ofinbred maize line NP2208 are altered or substituted. The transfer (orintrogression) of the trait(s) into inbred maize line NP2208 is forexample achieved by recurrent selection breeding, for example bybackcrossing. In this case, inbred maize line NP2208 (the recurrentparent) is first crossed to a donor inbred (the non-recurrent parent)that carries the appropriate gene(s) for the trait(s) in question. Theprogeny of this cross is then mated back to the recurrent parentfollowed by selection in the resultant progeny for the desired trait(s)to be transferred from the non-recurrent parent. After three, preferablyfour, more preferably five or more generations of backcrosses with therecurrent parent with selection for the desired trait(s), the progenywill be heterozygous for loci controlling the trait(s) beingtransferred, but will be like the recurrent parent for most or almostall other genes (see, for example, Poehlman & Sleper (1995) BreedingField Crops, 4th Ed., 172-175; Fehr (1987) Principles of CultivarDevelopment, Vol. 1: Theory and Technique, 360-376, incorporated hereinby reference).

The laboratory-based techniques described above, in particular RFLP andSSR, are routinely used in such backcrosses to identify the progenieshaving the highest degree of genetic identity with the recurrent parent.This permits to accelerate the production of inbred maize lines havingat least 90%, preferably at least 95%, more preferably at least 99%genetic identity with the recurrent parent, yet more preferablygenetically identical to the recurrent parent, and further comprisingthe trait(s) introgressed from the donor patent. Such determination ofgenetic identity is based on molecular markers used in thelaboratory-based techniques described above. Such molecular markers arefor example those described in Boppenmaier, et al., "Comparisons amongstrains of inbreds for RFLPs", Maize Genetics Cooperative Newsletter(1991) 65, pg. 90, incorporated herein by reference, or those availablefrom the University of Missouri database and the Brookhaven laboratorydatabase (see http://www.agron.missouri.edu, incorporated herein byreference). The last backcross generation is then selfed to give purebreeding progeny for the gene(s) being transferred. The resulting plantshave essentially all of the morphological and physiologicalcharacteristics of inbred maize line NP2208, in addition to the singlegene trait(s) transferred to the inbred. Preferably, the resultingplants have all of the morphological and physiological characteristicsof inbred maize line NP2208, in addition to the single gene trait(s)transferred to the inbred. The exact backcrossing protocol will dependon the trait being altered to determine an appropriate testing protocol.Although backcrossing methods are simplified when the trait beingtransferred is a dominant allele, a recessive allele may also betransferred. In this instance it may be necessary to introduce a test ofthe progeny to determine if the desired trait has been successfullytransferred.

Many traits have been identified that are not regularly selected for inthe development of a new inbred but that can be improved by backcrossingtechniques or genetic transformation. Examples of traits transferred toinbred maize line NP2208 include, but are not limited to, waxy starch,herbicide tolerance, resistance for bacterial, fungal, or viral disease,insect resistance, enhanced nutritional quality, improved performance inan industrial process, altered reproductive capability, such as malesterility or male fertility, yield stability and yield enhancement.Other traits transferred to inbred maize line NP2208 are for theproduction of commercially valuable enzymes or metabolites in plants ofinbred maize line NP2208.

Traits transferred to maize inbred line NP2208 are naturally occurringmaize traits, which are preferably introgressed into inbred maize lineNP2208 by breeding methods such as backcrossing, or are heterologoustransgenes, which are preferably first introduced into a maize line bygenetic transformation using genetic engineering and transformationtechniques well known in the art, and then introgressed into inbred lineNP2208. Alternatively a heterologous trait is directly introduced intoinbred maize line NP2208 by genetic transformation. Heterologous, asused herein, means of different natural origin or represents anon-natural state. For example, if a host cell is transformed with anucleotide sequence derived from another organism, particularly fromanother species, that nucleotide sequence is heterologous with respectto that host cell and also with respect to descendants of the host cellwhich carry that gene. Similarly, heterologous refers to a nucleotidesequence derived from and inserted into the same natural, original celltype, but which is present in a non-natural state, e.g. a different copynumber, or under the control of different regulatory sequences. Atransforming nucleotide sequence may comprise a heterologous codingsequence, or heterologous regulatory sequences. Alternatively, thetransforming nucleotide sequence may be completely heterologous or maycomprise any possible combination of heterologous and endogenous nucleicacid sequences.

A transgene introgressed into maize inbred line NP2208 typicallycomprises a nucleotide sequence whose expression is responsible orcontributes to the trait under the control of a promoter appropriate forthe expression of the nucleotide sequence at the desired time in thedesired tissue or part of the plant. Constitutive or inducible promotersare used. The transgene may also comprise other regulatory elements suchas for example translation enhancers or termination signals. In apreferred embodiment, the nucleotide sequence is the coding sequence ofa gene and is transcribed and translated into a protein. In anotherpreferred embodiment, the nucleotide sequence encodes an antisense RNA,a sense RNA that is not translated or only partially translated, at-RNA, a r-RNA or a sn-RNA.

Where more than one trait are introgressed into inbred maize lineNP2208, it is preferred that the specific genes are all located at thesame genomic locus in the donor, non-recurrent parent, preferably, inthe case of transgenes, as part of a single DNA construct integratedinto the donor's genome. Alternatively, if the genes are located atdifferent genomic loci in the donor, non-recurrent parent, backcrossingallows to recover all of the morphological and physiologicalcharacteristics of inbred maize line NP2208 in addition to the multiplegenes in the resulting maize inbred line.

The genes responsible for a specific, single gene trait are generallyinherited through the nucleus. Known exceptions are, e.g. the genes formale sterility, some of which are inherited cytoplasmically, but stillact as single gene traits. In a preferred embodiment, a heterologoustransgene to be transferred to maize inbred line NP2208 is integratedinto the nuclear genome of the donor, non-recurrent parent. In anotherpreferred embodiment, a heterologous transgene to be transferred to intomaize inbred line NP2208 is integrated into the plastid genome of thedonor, non-recurrent parent. In a preferred embodiment, a plastidtransgene comprises one gene transcribed from a single promoter or twoor more genes transcribed from a single promoter.

In a preferred embodiment, a transgene whose expression results orcontributes to a desired trait to be transferred to maize inbred lineNP2208 comprises a virus resistance trait such as, for example, a MDMVstrain B coat protein gene whose expression confers resistance to mixedinfections of maize dwarf mosaic virus and maize chlorotic mottle virusin transgenic maize plants (Murry et al. Biotechnology (1993)11:1559-64, incorporated herein by reference). In another preferredembodiment, a transgene comprises a gene encoding an insecticidalprotein, such as, for example, a crystal protein of Bacillusthuringiensis or a vegetative insecticidal protein from Bacillus cereus,such as VIP3 (see for example Estruch et al. Nat Biotechnol (1997)15:137-41, incorporated herein by reference). In a preferred embodiment,an insecticidal gene introduced into maize inbred line NP2208 is aCry1Ab gene or a portion thereof, for example introgressed into maizeinbred line NP2208 from a maize line comprising a Bt-11 event asdescribed in U.S. application Ser. No. 09/042,426, incorporated hereinby reference, or from a maize line comprising a 176 event as describedin Koziel et al. (1993) Biotechnology 11: 194-200, incorporated hereinby reference. In yet another preferred embodiment, a transgeneintrogressed into maize inbred line NP2208 comprises a herbicidetolerance gene. For example, expression of an altered acetohydroxyacidsynthase (AHAS) enzyme confers upon plants tolerance to variousimidazolinone or sulfonamide herbicides (U.S. Pat. No. 4,761,373,incorporated herein by reference). In another preferred embodiment, anon-transgenic trait conferring tolerance to imidazolinones isintrogressed into maize inbred line NP2208 (e.g a "IT" or "IR" trait).U.S. Pat. No. 4,975,374, incorporated herein by reference, relates toplant cells and plants containing a gene encoding a mutant glutaminesynthetase (GS) resistant to inhibition by herbicides that are known toinhibit GS, e.g. phosphinothricin and methionine sulfoximine. Also,expression of a Streptomyces bar gene encoding a phosphinothricin acetyltransferase in maize plants results in tolerance to the herbicidephosphinothricin or glufosinate (U.S. Pat. No. 5,489,520, incorporatedherein by reference). U.S. Pat. No. 5,013,659, incorporated herein byreference, is directed to plants that express a mutant acetolactatesynthase (ALS) that renders the plants resistant to inhibition bysulfonylurea herbicides. U.S. Pat. No. 5,162,602, incorporated herein byreference, discloses plants tolerant to inhibition by cyclohexanedioneand aryloxyphenoxypropanoic acid herbicides. The tolerance is conferredby an altered acetyl coenzyme A carboxylase(ACCase). U.S. Pat. No.5,554,798, incorporated herein by reference, discloses transgenicglyphosate tolerant maize plants, which tolerance is conferred by analtered 5-enolpyruvyl-3-phosphoshikimate (EPSP) synthase gene. U.S. Pat.No. 5,804,425, incorporated herein by reference, discloses transgenicglyphosate tolerant maize plants, which tolerance is conferred by anEPSP synthase gene derived from Agrobacterium tumefaciens CP-4 strain.Also, tolerance to a protoporphyrinogen oxidase inhibitor is achieved byexpression of a tolerant protoporphyrinogen oxidase enzyme in plants(U.S. Pat. No. 5,767,373, WO 97/32028 and WO 97/32011, all incorporatedherein by reference). Another trait transferred to inbred maize lineNP2208 confers tolerance to an inhibitor of the enzymehydroxyphenylpyruvate dioxygenase (HPPD) and transgenes conferring suchtrait are for example described in WO 9638567, WO 9802562, WO 9923886,WO 9925842, WO 9749816, WO 9804685 and WO 9904021, all incorporatedherein by reference.

In a preferred embodiment, a transgene transferred to maize inbred lineNP2208 comprises a gene conferring tolerance to a herbicide and at leastanother nucleotide sequence encoding another trait, such as for example,an insecticidal protein. Such combination of single gene traits is forexample a Cry1Ab gene and a bar gene.

Specific transgenic events introgressed into maize inbred line NP2208are found at http://www.aphis.usda.gov/bbep/bp/not₋₋ reg.htm1,incorporated herein by reference. These are for example introgressedfrom glyphosate tolerant event GA21 (application number 9709901p),glyphosate tolerant/Lepidopteran insect resistant event MON 802(application number 9631701p), Lepidopteran insect resistant eventDBT418 (application number 9629101p), male sterile event MS3(application number 9522801p), Lepidopteran insect resistant event Bt11(application number 9519501p), phosphinothricin tolerant event B16(application number 9514501p), Lepidopteran insect resistant event MON80100 (application number 9509301p), phosphinothricin tolerant eventsT14, T25 (application number 9435701p), Lepidopteran insect resistantevent 176 (application number 9431901p).

The introgression of a Bt11 event into a maize line, such as maizeinbred line NP2208, by backcrossing is exemplified in U.S. applicationSer. No. 09/042,426, incorporated herein by reference, and the presentinvention is directed to methods of introgressing a Bt11 event intomaize inbred line NP2208 using for example the markers described in U.S.application Ser. No. 09/042,426 and to resulting maize lines.

Direct selection may be applied where the trait acts as a dominanttrait. An example of a dominant trait is herbicide tolerance. For thisselection process, the progeny of the initial cross are sprayed with theherbicide prior to the backcrossing. The spraying eliminates any plantwhich do not have the desired herbicide tolerance characteristic, andonly those plants which have the herbicide tolerance gene are used inthe subsequent backcross. This process is then repeated for theadditional backcross generations.

Industrial Applicability

This invention also is directed to methods for producing a maize plantby crossing a first parent maize plant with a second parent maize plantwherein either the first or second parent maize plant is a maize plantof inbred line NP2208 or a maize plant of inbred line NP2208 furthercomprising one or more single gene traits. Further, both first andsecond parent maize plants can come from the inbred maize line NP2208 oran inbred maize plant of NP2208 further comprising one or more singlegene traits. Thus, any such methods using the inbred maize line NP2208or an inbred maize plant of NP2208 further comprising one or more singlegene traits are part of this invention: selfing, backcrosses, hybridproduction, crosses to populations, and the like. All plants producedusing inbred maize line NP2208 or inbred maize plants of NP2208 furthercomprising one or more single gene traits as a parent are within thescope of this invention. Advantageously, inbred maize line NP2208 orinbred maize plants of NP2208 further comprising one or more single genetraits are used in crosses with other, different, maize inbreds toproduce first generation (F1) maize hybrid seeds and plants withsuperior characteristics.

In a preferred embodiment, seeds of inbred maize line NP2208 or seeds ofinbred maize plants of NP2208 further comprising one or more single genetraits are provided as an essentially homogeneous population of inbredcorn seeds. Essentially homogeneous populations of inbred seed are thosethat consist essentially of the particular inbred seed, and aregenerally purified free from substantial numbers of other seed, so thatthe inbred seed forms between about 90% and about 100% of the totalseed, and preferably, between about 95% and about 100% of the totalseed. Most preferably, an essentially homogeneous population of inbredcorn seed will contain between about 98.5%, 99%, 99.5% and about 100% ofinbred seed, as measured by seed grow outs. The population of inbredcorn seeds of the invention is further particularly defined as beingessentially free from hybrid seed. The inbred seed population may beseparately grown to provide an essentially homogeneous population ofplants of inbred maize line NP2208 or inbred maize plants of NP2208further comprising one or more single gene traits.

As used herein, the term "plant" includes plant cells, plantprotoplasts, plant cell tissue cultures from which maize plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants or parts of plants, such as embryos, pollen, ovules, flowers,kernels, ears, cobs, leaves, husks, stalks, roots, root tips, anthers,silk, seeds and the like. Duncan, Williams, Zehr, and Widholm, Planta(1985) 165:322-332 reflects that 97% of the plants cultured thatproduced callus were capable of plant regeneration. Subsequentexperiments with both inbreds and hybrids produced 91% regenerablecallus that produced plants. In a further study in 1988, Songstad,Duncan & Widholm in Plant Cell Reports (1988), 7:262-265 reports severalmedia additions that enhance regenerability of callus of two inbredlines. Other published reports also indicated that "nontraditional"tissues are capable of producing somatic embryogenesis and plantregeneration. K. P. Rao, et al., Maize Genetics Cooperation Newslefter,60:64-65 (1986), refers to somatic embryogenesis from glume calluscultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347 (1987)indicates somatic embryogenesis from the tissue cultures of maize leafsegments. Thus, it is clear from the literature that the state of theart is such that these methods of obtaining plants are, and were,"conventional" in the sense that they are routinely used and have a veryhigh rate of success.

Tissue culture of maize is described in European Patent Application,publication 160,390, incorporated herein by reference. Maize tissueculture procedures are also described in Green and Rhodes, "PlantRegeneration in Tissue Culture of Maize," Maize for Biological Research(Plant Molecular Biology Association, Charlottesville, Va. 1982, at367-372) and in Duncan, et al., "The Production of Callus Capable ofPlant Regeneration from Immature Embryos of Numerous Zea maysGenotypes," 165 Planta 322-332 (1985). Thus, another aspect of thisinvention is to provide cells which upon growth and differentiationproduce maize plants having the physiological and morphologicalcharacteristics of inbred maize line NP2208. In a preferred embodiment,cells of inbred maize line NP2208 are transformed genetically, forexample with one or more genes described above, for example by using atransformation method described in U.S. application Ser. No. 09/042,426,incorporated herein by reference, and transgenic plants of inbred maizeline NP2208 are obtained and used for the production of hybrid maizeplants.

Maize is used as human food, livestock feed, and as raw material inindustry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry. Industrial uses of maize include productionof ethanol, maize starch in the wet-milling industry and maize flour inthe dry-milling industry. The industrial applications of maize starchand flour are based on functional properties, such as viscosity, filmformation, adhesive properties, and ability to suspend particles. Themaize starch and flour have application in the paper and textileindustries. Other industrial uses include applications in adhesives,building materials, foundry binders, laundry starches, explosives,oil-well muds, and other mining applications. Plant parts other than thegrain of maize are also used in industry: for example, stalks and husksare made into paper and wallboard and cobs are used for fuel and to makecharcoal.

The seed of inbred maize line NP2208 or of inbred maize line NP2208further comprising one or more single gene traits, the plant producedfrom the inbred seed, the hybrid maize plant produced from the crossingof the inbred, hybrid seed, and various parts of the hybrid maize plantcan be utilized for human food, livestock feed, and as a raw material inindustry.

The present invention therefore also discloses an agricultural productcomprising a plant of the present invention or derived from a plant ofthe present invention. The present invention also discloses anindustrial product comprising a plant of the present invention orderived from a plant of the present invention. The present inventionfurther discloses methods of producing an agricultural or industrialproduct comprising planting seeds of the present invention, growingplant from such seeds, harvesting the plants and processing them toobtain an agricultural or industrial product.

Performance Examples of Maize Inbred Line NP2208

In the examples that follow, the traits and characteristics of inbredmaize line NP2208 are presented as an inbred comparisons per se and asinbred by tester comparisons. The data presented is for keycharacteristics and traits and is reported from experiments where thecompared lines where grown side-by-side.

Inbred Comparisons

The data in table 2A show for example that inbred NP2208 issignificantly higher to the tassel tip and to the top ear node thaninbred A619, that inbred NP2208 has a significantly less lateral tasselbranches that originate from the central spike than inbred A619, inbredNP2208 has a significantly narrower ear at the midpoint than inbredA619, that inbred NP2208 has significantly lighter kernels than inbredA619, and that inbred NP2208 has a significantly narrower cob at themidpoint than inbred.

                                      TABLE 2A                                    __________________________________________________________________________    Comparison of inbreds NP2208 and A619                                                PLHCN                                                                             ERHCN                                                                             HU5SN                                                                             STBWR                                                                              LTBRN                                                                             ERDIN                                                                             KRWDN                                                                              K100N                                                                             COBDN                                __________________________________________________________________________    Grand Mean                                                                           219 68  1289                                                                              4.5  6   43  8    26  25                                     Trials w/data  7 7   6 1 7 7 7 7 7                                            LSD .05  12 5  49 1 2 2 1 2 2                                                 CV %  3 9   2 11.5 20  3 11  10  4                                            Probability %  0 0   8 0 0 0 0 0 0                                            NP2208 242 84  1268 4 2 40  7 24  22                                          A619 197 51  1309 5 10  46  8 28  28                                        __________________________________________________________________________

The data in table 2B show for example that inbred NP2208 is sheddingpollen significantly earlier than inbred MO17, that inbred NP2208 has asignificantly shorter tassel from top leaf collar to tassel tip thaninbred MO17, that inbred NP2208 has significantly shorter ears thaninbred MO17 and that inbred NP2208 has significantly lighter kernelsthan inbred MO17.

                                      TABLE 2B                                    __________________________________________________________________________    Comparison of inbreds NP2208 and MO17                                                PLHCN                                                                             ERHCN                                                                             HU5SN                                                                             HUPLN                                                                             LAERN                                                                             LTBRN                                                                             LTASN                                                                             ERLNN                                                                             KRRWN                                                                              KRWDN                                                                              K100N                        __________________________________________________________________________    Grand Mean                                                                           239 89  1381                                                                              97  6   4   48  16  13   8    28                             Trials w/data 7 7   6  3 7 7 7 7 7 7 7                                        LSD .05 6 5  38 24 0 1 4 1 1 1 2                                              CV % 3 7   1 22 9 30  6 5 8 11  9                                             Probability % 2 0   0  0 0 0 1 0 0 0 0                                        MO17 235  93  1494 116  5 6 52  18  11  9 31                                  NP2208 242  84  1268 78 6 2 45  13  14  7 24                                __________________________________________________________________________

The data in table 2C show for example that inbred NP2208 has asignificantly smaller common rust rating than inbred B73, that inbredNP2208 has significantly less lateral tassel branches that originatefrom the central spike than inbred B73, that inbred NP2208 hassignificantly narrower ear at the midpoint than inbred B73, that inbredNP2208 has significantly lighter husked ear than inbred B73, that inbredNP2208 has significantly less kernel rows than inbred B73 and thatinbred NP2208 has significantly narrower cob at the midpoint than inbredB73.

                                      TABLE 2C                                    __________________________________________________________________________    Comparison of inbreds NP2208 and B73                                                 PLHCN                                                                             ERHCN                                                                             HU5SN                                                                             HUPSN                                                                             CRSTR                                                                             STBWR                                                                              LTBRN                                                                             ERDIN                                                                             EWGTN                                                                              KRRWN                                                                              COBDN                       __________________________________________________________________________    Grand Mean                                                                           238 93  1337                                                                              1333                                                                              2.5 5    5   42  115  16   24                            Trials w/data 7 7   6   6 1 1 7 7  7 7 7                                      LSD .05 5 5  34  38 1.7 1 1 3  12 1 3                                         CV % 3 7   2   1 27.6 11.5 25  3  14 7 4                                      Probability % 0 0   0   0 0 0 0 0  0 0 0                                      B73 234  102  1406 1393 3.5 6 8 45  129 17  27                                NP2208 242  84  1268 1274 1.5 4 2 40  101 14  22                            __________________________________________________________________________

Inbred By Tester Comparison

The results in Table 3A compare inbred NP2208 and inbred X when eachinbred is crossed to the same tester line. For example, the NP2208hybrid has significantly higher grain yield expressed as bushels peracre adjusted to 15.5% grain moisture than the inbred X hybrid, theNP2208 hybrid has a significantly lower Grey leaf spot severity ratingthan the inbred X hybrid.

                  TABLE 3A                                                        ______________________________________                                        Comparison of inbred NP2208 crossed to tester inbredA                           and inbred B73 crossed to tester inbredX                                                YBUAN     HU5SN   STBWR   GRLSR                                   ______________________________________                                        Grand Mean  176.3     1358    3.4     4.9                                       Trials w/data 199 30 8 39                                                     LSD .05 3.7 14 1.2 0.4                                                        CV % 7.5 1 29 3.3                                                             Probability % 0 0 2.8 0                                                       Inbred A/Inbred X 172.9 1385 4.1 5.8                                          Inbred A/NP2208 179.8 1331 2.8 4.1                                          ______________________________________                                    

The results in Table 3B compare inbred NP2208 and inbred X crossed tothe same tester line. For example, the inbredY hybrid is significantlyearlier to shed pollen, extrude silk and reach physiological maturitythan the NP2208 hybrid and the inbredY hybrid has significantly lowergrain moisture at harvest than the NP2208 hybrid.

                  TABLE 3B                                                        ______________________________________                                        Comparison of inbred NP2208 crossed to tester inbredA                           and to tester inbredY                                                                  MST.sub.-- P                                                                           HU5SN   HUPSN  CRSTR GRLSR                                ______________________________________                                        Grand Mean 18.1     1340    1346   2.2   4.7                                    Trials w/data 200 30 30 3 39                                                  LSD .05 0.2 11 9 0.2 0.3                                                      CV % 4.7 1 1 4.9 3.4                                                          Probability % 0 0 0 0 0                                                       Inbred A/Inbred Y 17.9 1331 1326 2.3 4.1                                      Inbred A/NP2208 18.3 1349 1366 2 5.4                                        ______________________________________                                    

The results in Table 3C compare inbred NP2208 and inbred Z crossed tothe same tester line. For example, the NP2208 hybrid is significantlyhigher to the tassel tip and to the top ear node than the inbred hybridand the NP2208 hybrid has significantly lower grain moisture at harvestthan the inbredZ hybrid. NP2208 hybrid has significantly more stalksbroken below the ear at the time of harvest than the inbredZ hybrid.

                                      TABLE 3C                                    __________________________________________________________________________    Comparison of inbred NP2208 crossed to tester inbredA and to tester            inbredZ                                                                             YBUAN                                                                              MST.sub.-- P                                                                      STKLP                                                                             PLHCN                                                                             ERHCN                                                                             HU5SN                                                                             HUPSN                                                                             CRSTR                                                                             GRLSR                                 __________________________________________________________________________    Grand Mean                                                                           171.7                                                                              19.1                                                                              4   247 103 1297                                                                              1283                                                                              2   3.4                                     Trials w/data 95 96 67 22 22 17 17 3 20                                       LSD .05 4.1 0.3 1 6 6 13 11 0.3 0.3                                           CV % 7.3 4.4 82 2 5 1 1 10.5 19                                               Probability % 0 0 0 0 0 0 1 0 0                                               Inbred A/ 182.1 18.3 5 265 110 1285 1274 2.3 3.7                              NP2208                                                                        Inbred A/ 161.2 19.9 3 229 97 1309 1291 1.7 3.1                               Inbred Z                                                                    __________________________________________________________________________

Applicants have made a deposit of at least 2500 seeds of Inbred CornLine NP2208 with the American Type Culture Collection (ATCC), Manassas,Va., 20110-2209 U.S.A., ATCC Deposit No: PTA-449. The seeds depositedwith the ATCC on Aug. 3, 1999 were taken from the deposit maintained byNovartis Corporation, 3054 Cornwallis Road, Research Triangle Park, N.C.27709, since prior to the filing date of this application. This depositof the Inbred Maize Line NP2208 will be maintained in the ATCCdepository, which is a public depository, for a period of 30 years, or 5years after the most recent request, or for the effective life of thepatent, whichever is longer, and will be replaced if it becomesnonviable during that period. Additionally, Applicants have satisfiedall the requirements of 37 C.F.R. §§1.801-1.809, including providing anindication of the viability of the sample. Applicants impose norestrictions on the availability of the deposited material from theATCC; however, Applicants have no authority to waive any restrictionsimposed by law on the transfer of biological material or itstransportation in commerce. Applicants do not waive any infringement ofits rights granted under this patent or under the Plant VarietyProtection Act (7 USC 2321 et seq.). U.S. Plant Variety Protection ofInbred Maize Line NP2208 has been applied for under Application No.2000002234.

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas single gene modifications and mutations, somaclonal variants, variantindividuals selected from large populations of the plants of the instantinbred and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

What is claimed is:
 1. Seed of maize inbred line NP2208 having beendeposited with ATCC under Accession No: PTA-449.
 2. A maize plant, orparts thereof, of inbred line NP2208, seed of said line having beendeposited with ATCC under Accession No: PTA-449.
 3. Pollen of the plantof claim
 2. 4. An ovule of the plant of claim
 2. 5. A maize plant, orparts thereof, having all the physiological and morphologicalcharacteristics of a plant according to claim
 2. 6. A male sterile maizeplant, or parts thereof, otherwise having all the physiological andmorphological characteristics of a plant according to claim
 2. 7. Amaize plant, or parts thereof, according to claim 2, further comprisinga single gene transferred trait.
 8. A maize plant according to claim 7,wherein said single gene transferred trait comprises a heterologoustransgene.
 9. A maize plant according to claim 7, wherein said singlegene transferred trait comprises a gene conferring upon said maize planttolerance to a herbicide.
 10. A maize plant according to claim 9,wherein said herbicide is glyphosate, gluphosinate, a sulfonylurea or animidazolinone herbicide, a hydroxyphenylpyruvate dioxygenase inhibitoror a protoporphyrinogen oxidase inhibitor.
 11. A maize plant accordingto claim 7, wherein said single gene transferred trait comprises a geneconferring upon said maize plant insect resistance, disease resistanceor virus resistance.
 12. A maize plant according to claim 11, whereinsaid gene conferring upon said maize plant insect resistance is aBacillus thuringiensis Cry1Ab gene.
 13. A maize plant according to claim12, further comprising a bar gene.
 14. A maize plant according to claim12, wherein said Cry1Ab gene is introgressed into said maize plant froma maize line comprising a Bt-11 event or a 176 event.
 15. Seed of aplant according to claim
 7. 16. A tissue culture of regenerable cells ofa maize plant according to claim 2, wherein the tissue regeneratesplants capable of expressing all the morphological and physiologicalcharacteristics of plants according to claim
 2. 17. A tissue cultureaccording to claim 16, the regenerable cells being selected from thegroup consisting of embryos, meristems, pollen, leaves, anthers, roots,root tips, silk, flowers, kernels, ears, cobs, husks and stalks, orbeing protoplasts or callus derived therefrom.
 18. A maize plantregenerated from the tissue culture of claim 16, capable of expressingall the morphological and physiological characteristics of inbred lineNP2208, seed of said inbred line having been deposited with ATCC underAccession No: PTA-449.
 19. A method for producing maize seed comprisingcrossing a first parent maize plant with a second parent maize plant andharvesting the resultant first generation maize seed, wherein said firstor second parent maize plant is the inbred maize plant of claim
 2. 20. Amethod according to claim 19, wherein said first parent maize plant isdifferent from said second parent maize plant, wherein said resultantseed is a first generation (F1) hybrid maize seed.
 21. A methodaccording to claim 19, wherein inbred maize plant of claim 2 is thefemale parent.
 22. A method according to claim 19, wherein inbred maizeplant of claim 2 is the male parent.
 23. An F1 hybrid seed produced bythe method of claim
 20. 24. An F1 hybrid plant, or parts thereof, grownfrom the seed of claim
 23. 25. A method for producing maize seedcomprising crossing a first parent maize plant with a second parentmaize plant and harvesting the resultant first generation maize seed,wherein said first or second parent maize plant is the inbred maizeplant of claim
 5. 26. A method according to claim 25, wherein said firstparent maize plant is different from said second parent maize plant,wherein said resultant seed is a first generation (F1) hybrid maizeseed.
 27. A method according to claim 25, wherein inbred maize plant ofclaim 5 is the female parent.
 28. A method according to claim 27,wherein inbred maize plant of claim 5 is the male parent.
 29. An F1hybrid seed produced by the method of claim
 26. 30. An F1 hybrid plant,or parts thereof, grown from the seed of claim
 29. 31. A method forproducing maize seed comprising crossing a first parent maize plant witha second parent maize plant and harvesting the resultant firstgeneration maize seed, wherein said first or second parent maize plantis the inbred maize plant of claim
 7. 32. A method according to claim31, wherein said first parent maize plant is different from said secondparent maize plant, wherein said resultant seed is a first generation(F1) hybrid maize seed.
 33. A method according to claim 31, whereininbred maize plant of claim 7 is the female parent.
 34. A methodaccording to claim 31, wherein inbred maize plant of claim 7 is the maleparent.
 35. An F1 hybrid seed produced by the method of claim
 32. 36. AnF1 hybrid plant, or parts thereof, grown from the seed of claim
 35. 37.A method comprising:(a) planting a collection of seed comprising seed ofa hybrid, one of whose parents is a plant according to claim 2, or amaize plant having all the physiological and morphologicalcharacteristics of a plant according to claim 2, said collection alsocomprising seed of said inbred line; (b) growing plants from saidcollection of seed; (c) identifying plants of said inbred line; (d)selecting said plants of said inbred line; and (e) controllingpollination in a manner which preserves the homozygosity of said plantsof said inbred line.
 38. A method according to claim 37, wherein saidone parent is a plant of inbred maize line NP2208, seed of said linehaving been deposited with ATCC under Accession No: PTA-449, furthercomprising a single gene transferred trait.
 39. The method of claim 37,wherein said step of identifying said inbred plant comprises:identifyingplants with decreased vigor.
 40. A method comprising introgressing asingle gene trait into inbred maize line NP2208, seed of said linehaving been deposited with ATCC under Accession No: PTA-449, using oneor more markers for marker assisted selection among maize lines to beused in a maize breeding program, the markers being associated with saida single gene trait, wherein the resulting maize line is inbred maizeline NP2208 further comprising said a single gene transferred trait. 41.A method according to claim 40, wherein said a single gene traitcomprises a Cry1Ab gene and said markers comprise Z1B3 and UMC150a.